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From: "l.v.merzljak at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug c++/100897] Symmetric transfer does not prevent stack-overflow
 for C++20 coroutines
Date: Fri, 11 Jun 2021 10:33:53 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D100897

--- Comment #2 from Leonard von Merzljak <l.v.merzljak at gmail dot com> ---
(In reply to Iain Sandoe from comment #1)
> for symmetric transfer to work without stack overflow, it relies on an
> indirect tailcall.
>=20
> For some GCC targets indirect tail-calls are not available without some
> additional support (see PR94794).
>=20
> I tried to reproduce this (with a test case I use regularly for this) on a
> target that normally completes symmetric transfers successfully when the
> optimisation level is > 1. (x86_64, darwin).
>=20
> The fail also occurs with my regular test case with -fsanitize=3Daddress =
- so,
> it seems that the inclusion of the address sanitiser is preventing or
> interfering with the tailcall.  Note that there are also other known issu=
es
> with coroutines and the sanitizers (PR95137).

Thank you for your comment. I tried it out and can confirm that I don't get=
 a
stack-overflow anymore if I omit -fsanitize=3Daddress and use an optimizati=
on
level > 1. If the issues with coroutines and sanitizers are already known, =
then
this bug report can be marked as resolved.
Of course, it would be nice if the stack-overflow would not occur even when
using an optimization level <=3D 1, but this probably does not qualify as a=
 bug.=